1. Field of the Invention
The present invention relates to a dry treatment method and apparatus for causing an object to be treated such as a semiconductor wafer or LCD glass substrate to contact with a drying gas to thereby dry the object.
2. Description of the Related Art
Generally, in the process of manufacturing a semiconductor in a semiconductor manufacturing apparatus, there is widely adopted a method of immersing the surface of an object to be treated such as a semiconductor wafer or LCD glass substrate (hereinafter referred to as "a wafer") in a chemical liquid, rinsing liquid (cleaning liquid) and the like by the use of a cleaning treatment apparatus to thereby perform a cleaning treatment with respect thereto and thereafter drying the cleaned wafer by the use of a dry treatment apparatus.
Conventionally, as this type of drying treatment apparatus, there is known an apparatus which is equipped, at a low side thereof communicated with a drying treatment section, with a drying gas producing means for heating a volatile organic solvent such as IPA (isopropyl alcohol) and thereby generating a vapor thereof. The IPA gas as a drying gas is caused to contact with an object to be treated such as a cleaned wafer that has been accommodated within the drying treatment section. The vapor of the drying gas is then condensed and any moisture on the object is removed, whereby the object is dried. In this type of drying treatment method, the degree of drying is greatly affected by the concentration of the drying gas or the degree of contact of the drying gas with the object.
In this type of conventional drying treatment apparatus, the drying gas producing section and the drying treatment section are located in the same zone, so that the state of the drying gas produced in the drying gas producing section tends to be affected by the condition within the drying treatment section. For this reason, heat is taken away by the cleaned object to be treated which is at a low-temperature, with the result that the vaporization of the organic solvent is suppressed. Furthermore, the heat of the vapor that has been obtained by the vaporization is taken away in the vicinity of the object to be treated, so that the temperature of the vapor is lowered and the vapor is condensed. Therefore, there occurs a state in which no drying gas exists within the drying treatment section or a state in which the concentration of the drying gas is very low even if the drying gas exists, giving rise to a problem that the drying efficiency becomes low. If the drying gas continues to be produced in spite of the above-mentioned state, the amount of consumption of the organic solvent will increase undesirably.